1. Technical Field
The disclosure relates to a bearing device that includes a bearing portion and an oil supply unit that is provided adjacent to the bearing portion in an axial direction.
2. Description of Related Art
In recent years, various machine tools have been required to have a spindle that rotates at higher speed in order to improve machining efficiency and productivity. When the spindle rotates at high speed, lubrication properties are important especially at a bearing portion that supports the spindle. Thus, there is proposed a bearing device including an oil supply unit provided in a spacer that is provided adjacent to a bearing portion in an axial direction (see Japanese Patent Application Publication No. 2014-219078 (JP 2014-219078 A)). The oil supply unit includes a tank that stores lubricating oil, and a pump that discharges the lubricating oil in the tank to an annular space between an inner ring and an outer ring.
The oil supply unit of the bearing device described in Japanese Patent Application Publication No. 2014-219078 (JP 2014-219078 A) further includes a temperature sensor and a control unit (a microcomputer) in addition to the tank and the pump. The oil supply unit is configured such that a detection signal of the temperature sensor is input to the control unit, and the control unit controls the pump to adjust the amount of lubricating oil supplied to the bearing portion.